In designing communications busses, engineers incorporate physical redundancies to provide operational safety and incorporate data redundancies to insure informational integrity. Commonly, multiple lanes with two or more processors in each lane are used to provide this redundancy.
A communications bus may include dual independent lanes, each with a primary processor and a checking processor (i.e. a backup processor). Each of the primary and checking processors may provide identical output signals in response to input signals from one or more sensors representative of characteristics of an aircraft or other complex system. These output signals are commonly compared to one another to determine if a data error has occurred during processing by the primary and checking processors.
Systems engineers conventionally ensure that data errors do not produce systems failures by incorporating self checking, multiple rail features into system data busses. These self-checking features typically use a comparator sub-circuit where multiple, independent and normally identical data messages are compared on a bit-by-bit or on a packet-by-packet basis in their entireties. Conventional methods typically require that each of two complete and identical component sequences be transmitted across a separate rail of a multiple rail (i.e. multiple paths) bus, which necessarily consumes a certain amount of valuable bandwidth.
For example, the outputs of a first and a second primary processor may be monitored with respect to each other and a comparison signal resulting therefrom may be generated. A comparison process may be conducted between a first and a second redundant processor. Similarly, signals generated by the primary processor and its corresponding redundant processor may also be compared. As such, the bandwidth required to pass these redundant signals along a single data bus may increase geometrically with the number of processors.
Accordingly, it is desirable to achieve data integrity verification in a more efficient manner. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.